Screen holder



Oct. 23 1923.

H. BOWEN SCREEN HOLDER 1921 2 Sheets-Sheet 1 Filed Nov, 14',

en/T01" f 71815011 130v;

Oct. 23 1923.

H. N. BOWEN S GREEN HOLDER Filed Nov. 14 1921 2 Sheets-Sheet 2 7 720311. Zbr

Her/Jeri l'ielsmz Bozue 11.

Patented Oct. 23, 1923.

UNITED- STATES T all whom it may concern:

Be it known I, linnnnn'r Nnnson BOWEN, a citizen of the United States, re-

siding at Lakcview, \Vhite Bear Lake. in the county of Washington and State of Minncsotn, have invented a new and useful Screen Holder, of which the following is a specilication.

My invention relates to improvements, in screen holders.

In every engraving shop Where photo engravings are produced, various ordinary square screens with different rulings from 59 lines to the inch to 200 lines to the inch are required. These screens are veryexpensive and are generally confined to use in the production of black and White engrav; ings. In making negatives in the production of two, three and four color work, circular screens, ruled like the ordinary square screens, are ordinarily employed. These circular screens, of course, provide for the making of negatives of relative maximum dimensions at the various angles of said screens, but the primary purpose of their circular shape is to provide for supporting the same, whereby they may be readily positioned at various angles to produce the desired color process negatives. Circular screens being so; much more expensive than the ordinary sqr are screens, the acquisition thereof, even by concerns having a relative ly large output, is often rohihitive, the result being that large volumes negative work in color process procedure are necessarily delegated by many small concerns to larger institutions having the requisite equipment.

The primary object of my invention is to provide a screen holder for application to cameras, the some being adapted to 'novably recelve the ordinary square, hell;

tone screens of various dimensions and to locate the same in different angular relations whereby color process ncy itives may be readilyproducedtherewith. f

With the foregoing and other ob ects in view, which will appear in the following description. the invention resides in the novel combination and arrangement of parts and in the details of: construction hereinafter described and claimed.

In the drawings, Fig. 1 is a view in elevze tion illustrating a device embodying: my vention and applied to a. camera; Fig. 2 is a similar view, the screen holder member Serial Referring to the d .,s, ii: have umd the reference letter A indicate the frame or support imoroved device and the letter B to de igi'iiae screen holder associated therewith. The frame A comprises a plate adapted to he applied to a camera as shown in Fig. the margins of the plate, in Worlrin "I (:Sitlikfi, embraced by the ordinary frame holdi g; flo ers ll) of the camera. The screei holder a comprises beveled Rollers l2 he face of the ironic, grooved K receive the hoveied P). these rollers. n of the piste A iticui. e or t ro hose 1 A in o. holder B. beveled to c edge portion 0 with slot 18 in. the IL A set screw in said lug, stir. having :1 shoulder seizing toe slot l8 in; the r volt time A, pn'ovides for clen hug the base 15 in normal t ion (Fir and permits oi treeir said hsscso that the some may he .ivith dge o the holder l prc 'izirct 1 from the rollers c) iii E... inc:

one, v. i inner licvelu is Isolde, ii and is former (1 .L'

1.. uttingz closely in a. v

dovetailguide in i. 22 is mounted. Said Q to rm a jaw nieinhe" to outer beveled edge portion of the hoh (Fig. at}. A binding screw 9.5 {three n the base A and hearing inst thoreurvwiriflly turneiil shoulder 252 the slide, 2i---ser 9s ml to chin p said against the holtcr causing said. holder to ipped lac-mean the two jaw members 16 and 23 of the guide C and thereby secured against accidental. angular movement on the frame A. Rc leasing the binding screw 23 results in freeing the slide 22, so that the holder can be turned, as desired. A line 24 on the outer face slide 21? supplies a mark of reference employed in adjusting the holder B. On the margin of the holder B are similar lines 23. the use of which will soon appear.

The holder B is formed with a central screen receiving openings 24:. rectangular in shape, to receive a rectangular screen as at S. The frame A is also formed with a central opening 25, registering with the opening 24 in the holder. 13, said opening 25 being of such dimensions as to avoid obstructing the opening 24 in said holder. Screen frame and adapter holding devices D are supplied at each margin of the screen opening 24. Each device includes a clip 26 attached to the holder B by means of a bolt 27 as shown in Fig. 5. A stem 28 slides in the clip 26 and is fitted with an abutment 29. A spring 30' encircling the stem 28 and interposed between the clip 26 and abutment 29 yieldingly urges the latter forward. A mutilated disc-like head 30, seated in a depres; sion 31 in the holder B and revolubly held in such position by the bolt- 2i. overlaps the edge of the screen opening 24 in all of its angular positions excepting one position.

whcrein said head is entirely withdrawn from said opening. Diametrically opposed recesses 31 in the heads 30 receive the lugs 3240f a spanner key 33 employed in turning the same. \Vith the heads 30 turned to avoid obstructing the screen opening 2- a screen frame may be placed against the yielding abutments 29 and pressed rearwardly a suite cientdistance to allow the heads 30 to be turned into overlapping locking positions (Figs. 1 and 2).

It will be noted that the outer faces of the rollers 12, frame securing heads- D and clamping guide C lie flush with the face of the holder B. This provision permits a close arrangement of camera plates with respect to screens carried in the holder B.

The marks 23' on the holder are made with respect to the rectangular screen opening 24. An ordinary rectangular screen. in place within the holder B. is held in position wherein the diagonal lines thereof rest at 45, when the 45 line 2. on the holder B coincides with the reference line 24: on the slide 22 (Fig. 1). This position of a screen is required to produce a black negative for color process work. Shifting the holder B to move the 90 and 105 lines 23 into registration with the reference line 24 respectively locates the lolder B in proper positions for the production of blue. yellow and red negatives for color process work.

My improvement is advantageous, among other things, for the following reasons: It enables a producer, equipped only with the ordinary square, half tone screens, to increase his capacity, at little expense, by adding an output otherwisenecessitating great expense. It minimizes the cost of color work to the consumer by saving in the cost of production. The improvement is conveniently applied to a camera. It readily accommodates the various ordinary square, 'half tone screens and provides for quickly and accurately adjusting the same to the various angular positions required to produce the various color process negatives.

Changes in the specific form of my invention, as herein disclosed, may be made within the scope of what is claimed without dcparting from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In a device of the class described, an angularly adjustable circular holder formed with a screen receiving opening therein, a mounting for said holder applicable to a camera and arranged to avoid obstructing the opening in said holder, said mounting including a plurality of combination supporting and retau iig rollers engaging the margin of said heater and 'means for locking the holder in various angular positions, said rollers and holder locking means being confined within limits at the rear of a plane closely paralleling the face of said holder.

2. A-supporting plate designed to co-act with screen securing devices within a camera-and formed with an opening theret-hrough. a second plate parallel with the first and comprising a screen holding member. the same being formed with a screen receiving opening therein registering with the Opening in said supporting plate, means on the supporting plate supplying a revoluble mounting for the screen holding member. means for locking said member in various angular ,relations with respect to the supporting plate and yielding means on the holding member for securing a screen in position within the opening therein, said means including spring pressed abutments and locking heads opposed thereto, said parts being adapted to grip opposite sides of a screen frame. the abutments being yieldable to accommodate screen frames of various thicknesses and the locking heads being arranged to locate the faces of the various screens in a plane in approximate coincidence with theface of the holding member.

3. In a device of the class described, a frame removablv applicable to. a camera. housing. a circular holder member having a rectangular openingtherein unobstructed by said frame, means on. the frame for revolubly supporting the holder in parallelism with and in close proximity to the fra1ne,'means 0n the holder to secure screens in position registering with the opening therein and'means on the frame to secure the holder" against rotation with respect thereto, said holder supports, screen securing and holder locking means being confined within limits at the rear of a plane flush with the face of said holder.

4. In a device of the class described, a frame removably applicable to a camera housing, a holder member having an opening therein unobstructed by said frame,

means on the frame for revolubly supporting the holder in parallelism with and in close proximity to the frame, means on the holder to secure screens within the o ning therein and means to secure ther omer against rotation with respect to the frame, said holder supports, screen securing and holder locking means being confined within limits at the rear of a plane closely paralleling the face of said holder, whereby said face of said holder may be brought into the immediate proximity of a plate used in connection' therewith.

In testimony whereof, I have signed my name to this specification. I

HERBERT NELSON. BOWEN; 

